20142014 Ericsson AB. All Rights Reserved. The contents of this file are subject to the Erlang Public License, Version 1.1, (the "License"); you may not use this file except in compliance with the License. You should have received a copy of the Erlang Public License along with this software. If not, it can be retrieved online at http://www.erlang.org/. Software distributed under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the specific language governing rights and limitations under the License. Character Set and Source File Encoding character_set.xml
Character Set

In Erlang 4.8/OTP R5A the syntax of Erlang tokens was extended to allow the use of the full ISO-8859-1 (Latin-1) character set. This is noticeable in the following ways:

All the Latin-1 printable characters can be used and are shown without the escape backslash convention.

Atoms and variables can use all Latin-1 letters.

 Octal Decimal   Class 200 - 237 128 - 159   Control characters 240 - 277 160 - 191 - ¿ Punctuation characters 300 - 326 192 - 214 À - Ö Uppercase letters 327 215 × Punctuation character 330 - 336 216 - 222 Ø - Þ Uppercase letters 337 - 366 223 - 246 ß - ö Lowercase letters 367 247 ÷ Punctuation character 370 - 377 248 - 255 ø - ÿ Lowercase letters Character Classes.

In Erlang/OTP R16B the syntax of Erlang tokens was extended to handle Unicode. To begin with the support is limited to strings, but Erlang/OTP 18 is expected to handle Unicode atoms as well. More about the usage of Unicode in Erlang source files can be found in STDLIB's User's Guide.

Source File Encoding

The Erlang source file encoding is selected by a comment in one of the first two lines of the source file. The first string that matches the regular expression coding\s*[:=]\s*([-a-zA-Z0-9])+ selects the encoding. If the matching string is not a valid encoding it is ignored. The valid encodings are Latin-1 and UTF-8 where the case of the characters can be chosen freely.

The following example selects UTF-8 as default encoding:

%% coding: utf-8

Two more examples, both selecting Latin-1 as default encoding:

%% For this file we have chosen encoding = Latin-1
%% -*- coding: latin-1 -*-

The default encoding for Erlang source files was changed from Latin-1 to UTF-8 in Erlang OTP 17.0.